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To the prop experts : any idea if there would be a significant performance difference in having a 4 blade prop ? currently theres a vengeance stainless on my 115 hp merc 4 stroke..the engine is a 2006 efi. its all stock.. I havnt timed it but is not fast to plane..plenty of bow rise..thanks for your input.

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I think the addition of trim tabs (if you don't have them) would be a much better investment than a 4-blade prop. This would help the bow rise and also lower your planing speed and improve all-around performance much more dramatically than any prop. You also don't state what your WOT engine speed is. Too much pitch will also make you slow out of the hole.

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As a previous owner of a Dauntless 16 and assuming the hull is virtually the same I believe the propeller change to be a far better solution than trim tabs on that little hull. I understand the hull/transom notch on my hull was eliminated in newer hulls.

Tom W Clark was kind enough to recommend a specific stainless steel Stiletto four blade propeller for my application and he sold me one for a very good price. With the Stiletto and my Evinrude 115 HP two stroke DFI engine the boat literally leaped out of the hole when power was applied. Minimum speed on plane was reduced as well. There was a one to two MPH top speed loss but it was worth it to me for such improved performance. I spent very little time running at WOT.

Certainly small electric trim tabs could be installed on the 16 but there is really no room for hydraulic tabs. The lateral stability of that hull while underway would make the tabs more of a nuisance than anything else. I'm just guessing but I imagine the cost of installing tabs would be a good bit higher than a new propeller.

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Prop pitch would have the greatest effect on time to plane.
Motor mounting height and motor trim would have the most effect on bow rise and then time to plane.
Some 4 blade props do have stern lifting properties, but that is mostly noticed once on plane.
I think any "good" prop on a motor at the proper mounted height and trim angle might be better than an optimum prop on a motor mounted and trimmed incorrectly.
I highly respect any prop recommendation by Tom W Clark on these size Whalers.

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Appreciate direction on topic thus far..I realize i will need to supply engine mount position, prop pitch etc for further discussion. I will provide this as soon as i uncover it.. wot is 36 on the gps..5800 rpms..Butch, like you, i am not very concerned about wot, as i never really can open it up on the ocean up here..once on the water i can get time to plane numbers to compare..the stern on this hull has a deadrise of 14 .dont know if tabs would be of benefit..thanks all

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I would recommend you take a serious look at the brand new 4 blade Mercury Spitfire X7 prop. It is new design technology that Mercury says is the fastest top end, and best accelerating prop available for a Mid range outboard.
See mercurymarine.com for info.

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Send Tom Clark an email. He is a frequenter and poster on this forum. Do a search for his email. The X7 sounds interesting but get his $.02 on it. Get your data ready before contacting him. WOT RPM, engine and gear ratio, GPS speed at WOT, mounting height, and current prop are all useful to the gurus.

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Thanks you guys again for your advice and recommendations..I like reading about Mercs technology and quality, its very interesting. Will be good to see if theres a significant performance enhancement as an option..Will get my s*%t together and fwd to tom, regards

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Bob -

There will not be a significant change in performance.

In addition to engine height.....

There is no such thing as a stock prop. What do you have now?

What is your typical load in the boat? Fuel, people, gear etc? Where do people sit?

What is your typical engine trimming technique?

What is your throttle technique for increasing from headway to planing speed?

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Phil,

In experience there MAY very well be a significant change in performance depending upon how one defines significant. In my case changing to an optimum propeller and engine height resulted in a very significant change in acceleration and hole shot.

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I think I wiffed that reply.

(wiff is a term we used as kids when playing baseball and the batter swung and didn't come close to hitting the ball)

I agree with Butch. Dialing in the motor height and selecting the right prop can be a huge difference.